Method of withering tea-leaves.



. Patented-Mar. 4, |902. E C. U. SHEPARD. METHOD DF'WITHEBING TEA LEAVES.

(Application led July 81, 1901.) 'um mmm.) 2 shun-sm; 1

i l l 0.694,795. Patgnted Mar.74, 1902A.

l c. sue-PAM.

METHDD 0F WITHERINIG TEA LEAVES.

' (Appumion med July s1, 1901,) v

(llo Model.) 2 Sheets-Sheet 2.

UNITED *STATES PATENT OFFICE's CHARLES U. Sl-IEPARD, OF SUMMERVYILLvR-SOUTH CAROLINA.

xvii-:THon oF wiTHsRiNc TEA-LEAVES.

SPECIFICATION forming part of Letters Pad-,entr No. 694,795, dated March 4, 1902. apparsa nea any s1, 1901.' sein No. 70,435. ou Specimens.)

To all wiz/07u zit/,may concern:

Be it known that I, CHARLES U. SHEPARD, a citizen of the United States, residing at Summervilledn the county of Dorchester and State.

of South Carolina, have invented a new and useful Method of Withering Tea-Leaves, of which the following is a specification.

This invention relates to a method of treating green or freshly-picked tea-leaves under the procedure of which those` enzyms that are productive of destructive oxidationare sterilized or destroyed, those favorable to the iiavoring-oil of the tea are conserved, and withering of the leaves is'effected in a manner best to adapt them for subsequent rolling.

As is well known, green tea-leaves contain different kindsof en'zyms, certain of which are favorable to the Havering-oil of the tea and have to be retained in order that the 1innary to rolling the fresh leaf, and proper rolling is an indispensable concomitant in the thorough curing of the tea and depends for its success upon the degree of perfection of the withering. Heretofore withering has been accomplished in several different ways, all of which are primitive in character and require the expenditure of much time .and labor in their consummation. Among the different procedures employed maybe mentioned those of exposing the leaves in thin layers to the action of atmospheric air, as by spreading them upon floors, shelves, and the like, the steaming of the leaves over kettles of boiling water or in steam-chests, the roasting of the leaves in pans 'arranged over asl'ow lire, and, in additionv tojeither of the steps named and in conjunction with any one of them, the throwing of the leaves into the air several hundredy l times to bring them into the desired condi-` tion for rolling. The desideratum of each of the above-named procedures is to bring the elastic and more or less firm fresh leaves to a daccid state, in which they resemble in feel an old kid glove, and this condition is best attained where the leaves are thrown upward in to the air, effecting thereby a thorough separationleat by leaf and by the'slight jar or struction of oXidizing-enzyms, conservation of Vthose enzyms favorable to the Haveringoil of the tea, and the proper withering of the leaves, as will belliereinafter fully described,

and particularly pointed out in the claims.

In the accompanying drawings, forming a partof this specification, and in which like numerals of reference indicate corresponding parts,'there is illustrated a form of apparatus capable of carrying the method into effect, it being understood that the invention is not to be limited to any particular form of apparatus in edecting its consummation, and in these drawings' Figure 1 is a view in side elevation, partly in section, exhibiting a form of apparatus for carrying out the method.` Fig. 2 is an end View of the withering-cylinder, showing more particularly the arrangement of the flights therein by which the leaves are picked up and dropped continuously throughout the length of the cylinder or drum. l

Referring l to the drawings, l designates the cylinder, which may be constructed of a single length of tubing or in separate lengths suitably assembled. The cylinder is provided near each end Witha circumferential doubleflanged track 2 to engage roller-bearings 8, supported upon a suitable framework 4. Intermediate of the ends of the length of the cylinder is arranged a toothed band 5 to be engaged by a sprocket-chain 6, the same passing around a sprocket-wheel 7, carried by a vshaft 8, the shaft being provided with a band' wheel 9, which is to-be connected with a suitable source of power through a belt not necessary to be shown. The front end of the cylinder is somewhat constricted, as at 10, and projects within a cone-shaped pipe or flue il, through which air, either hot or cold,

is supplied to the cylinder. The pipe ll has associated with it a feed-chute 12, the upper ICG end of which carries a hopper 13 and the tion 16, with which connects a pipe 17, leading to the casing of an exhaust-fan 18, the fan being driven from a suitable source of power (not shown) through a pulley 19, the fan operating to set up a suction within the cylinder l, and thereby draw therethrough air, either hot or cold, as may be required. The casing 14 is provided with a door 20, by which access may be had thereto for the purpose of removing the treated leaves.

Secured to the inner walls of the cylinder is a series of spirally-arranged flights the depending flanges of which are by preference curved, as at 22, to augment the capacity of the iiights for picking up the leaves, the curved portions further operating to effect mechanical separation of the leaves. As herein shown, the nights are curved sufficiently to give a quarter-turn in the length of the cylinder; but it is to be understood that the degree of curvature may be varied to suit the requirements arising in the use of the apparatus.

In operation the green tea-leaves are fed into the hopper 13 and thence to the cylininder, where they are caught up by the flights and are rapidly and continuously dropped through the width of the diameter of the cylinder up to the discharge end thereof, the degree of rapidity of agitation and dropping being governed by the speed at which the cylinder is rotated, the operation being continuous-that is to say, the leaves are not retainedin a prescribed zone, but are constantly moving onward to the discharge, so that there could be a continuous supply of fresh leaves to the hopper and a continuous discharge of withered leaves into the casing 14. In their passing through the cylinder the leaves are individually subjected to the combined actionof air passing through the cylinder and to a slight pounding action resulting from their fall through the width of the cylinder and also by contact with each other in falling, so that by the time a leaf has passed through the cylinder it will be found to be perfectly withered and in best possible cons' dition for rolling and twisting.

temperature with the falling leaves in their progressive onward movementl to the discharge effecting proper withering without complete drying. By causing a rapid drop in the temperature of the air or withering medium destruction of those enzyms favorable to the flavoring-oil of the tea is obviated, so that the finished product will not have any of those elements requisite to a delicate and highly-flavored article in the least injured. There is therefore, as will be apparent, under this procedure, as practiced, iirst the destruction or sterilization of the oXidizing-enzyms, followed by the withering and workin g of the leaves to bring them mechanically to the condition best adaptedfor rolling and twisting, and the operations being continuous and very rapid effects an enormous saving in time and labor in the production of the finished product. It is of course well known that tea has heretofore been confined in a revolving cylinder provided with flights or shelves and subjected therein to the action of heated air or steam; but this is widely different from the present procedure, inasmuch as in the practiced art referred to there is no onward movement of the leaves toward a discharge under a rapidly-decreasing temperature, but, on the contrary, they are confined within the drum or cylinder untilv properly dried and withered, after which they are removed in bulk, necessitating a stoppage of the machinery. It will be readily seen that under such treatment were a degree of heat applied to the leaves to destroy the oxidizing enzyms that destruction of those enzyms favorable to the iiavoring-oil of the tea would inevitably follow, thereby defeating the very object of the present invention.

In order that the apparatus of this procedure may be adapted for treating leaves of different characters-as,- for instance, black tea-leaves or green tea-leaves-this may be effected by adjusting the temperature and speed of the air-current, or by changing the speed of revolution per minute of the cylinder, or by altering the number, form, or spirality of the flights in the cylinder, thereby varying the movements of the tea-leaves.

It will be seen from the foregoing description that the tea-leaves are mechanically subjected to all the treatments heretofore manually conducted and that the result is obtained more rapidly and with a greater evenness of output of the product than could possibly result from the practiced modes heretofore in vogue, and, further, that the procedure may be carried out equally well in wet weather as in dry, thereby saving in time and preventing any deterioration in the leaves which might result if not subjected to treatment very shortly after having been removed from the plants.

I-Iaving thus fully described my invention, what I claim as new, and desire to secure by Letters Patent,is-

1. The herein-described method of wither- IOO cernesV ingtea-leavesf-whichconsists in taking the fresh leaves, passing themv through an inclosed space, and subjecting them therein to agitation with progressive onward movement,Y in the presence of a currentof suitably-tem pered air.

2. The herein-described method of'wvithering tea-leaves, which consists in taking the fresh leaves, passing them through' an inclosed space, picking up and dropping the leaves Within theV space and at the same time imparting progressive onward movement thereto in the presence of a current of snitably-tempered air.

3. The herein-described method of Withering green tea and'of destroying the oxidizingenvzyms thereof, which consists in passing the' fresh leaves to 'an inclosed space, subjecting them at their pointof entranceto a current' of highly-heated air, and then picking up and dropping the leaves Within the space While imparting progressive onward movement there-V to toward theA discharge.

Vet. The herein-described method' of withering green tea, of destroying the oxidizing-enzyms thereof and conserving those favorable to the avoring-oil of the tea, which consists inV passing the I fresh leaves to anv inclosed space, subjecting them at their point of entrance to a current 'of highly heated air, and then picking up and droppingthe leaves within the space with decreasing temperature While imparting progressive onward movement thereto toward the discharge'.

In'testimony that vI'claim the foregoing as my own Ihavehereto affixed my signature in the presence of two Witnesses. Y,

p e CHARLES sHEPRD.

Witnesses: l' f ISAAC AULD,

- Y .THOMAS W. M CGILL, 

